The Floor Is Your Canvas

What Is Terrazzo: Terrazzo is a composite material, poured in place or precast, which is used for floor and wall treatments. It consists of marble, quartz, granite, glass, or other suitable chips, sprinkled or unsprinkled, and poured with a binder that is cementitious, chemical, or a combination of both. Terrazzo is cured and then ground and polished to a smooth surface or otherwise finished to produce a uniformly textured surface. It is easy to care for and a perfect flooring choice for residential or commercial purposes. The floor is your canvas and offers the ability to create a frame that can be designed right into the floor where any artistic element or theme is possible.

Terrazzo artisans create walls, floors, patios, and panels by exposing marble chips and other fine aggregates on the surface of finished concrete or epoxy-resin. Much of the preliminary work of terrazzo workers is similar to that of cement masons. Marble-chip, cementitious terrazzo requires three layers of materials. First, cement masons or terrazzo workers build a solid, level concrete foundation that is three to four inches deep. After the forms are removed from the foundation, workers add a one-inch layer of sandy concrete. Before this layer sets, terrazzo workers partially embed metal divider strips in the concrete wherever there is to be a joint or change of color in the terrazzo. For the final layer, terrazzo workers blend and place into each of the panels a fine marble chip mixture that may be color-pigmented. While the mixture is still wet, workers toss additional marble chips of various colors into each panel and roll a weighted roller (100–125 lbs.) over the entire surface.

Today, most of the terrazzo installed is epoxy terrazzo. The advantages of this material over cementitious terrazzo include a wider selection of colors, 1⁄4 inch to 3⁄8 inch installation thickness, lighter weight, faster installation, impermeable finish, higher strength, and less susceptibility to cracking. The disadvantage of epoxy resin–based terrazzo is that it can only be used for interior, not exterior, applications. Epoxy-based terrazzo will lose its color and slightly peel when used outdoors, whereas cement-based terrazzo will not. In addition to marble aggregate blends, other aggregates have been used, such as mother of pearl and abalone shell. Recycled aggregates include: glass, porcelain, concrete, and metal. Shapes and medallions can be fabricated on site by bending divider strips, or off site by water-jet cutting.

When the terrazzo is thoroughly dry (or cured in the case of thin-set terrazzo), helpers grind it with a terrazzo grinder, which is somewhat like a floor polisher, only much heavier. Slight depressions left by the grinding are filled with a matching grout material and hand-troweled for a smooth, uniform surface; it is then cleaned, polished, and sealed.[1]

Sample: Design Process: This Uptown Train Station and City Hall located in Normal, IL is anything but Normal. Being known as the second busiest Amtrak station in Illinois, and the City Hall of Normal, terrazzo was the first choice for flooring. A clean and simple color scheme was chosen on the ground floor in order to complement the focal point, an intricate terrazzo graphic of a compass with retro depictions of trains, buses, cars and pedestrians. The floor layout follows a radius design throughout, tying together both ramped floors and precast treads and risers. This 12,000 square-foot of 3/8” epoxy terrazzo in nine colors is built to last 100 years.